The magnetic field and internal structure of Ganymede (original) (raw)
- Letter
- Published: 12 December 1996
Nature volume 384, pages 544–545 (1996)Cite this article
- 1300 Accesses
- 113 Citations
- 199 Altmetric
- Metrics details
Abstract
BEFORE the recent fly-bys of Ganymede by the Galileo spacecraft, viable models of the internal structure of Jupiter's largest moon ranged from a uniform mixture of rock and ice to a differentiated body with a rocky core and an icy mantle1. Analysis of the Doppler shift of radio signals from Galileo has now shown that Ganymede is strongly differentiated with a relatively dense core surrounded by a thick shell of ice2. Other instruments have revealed that Ganymede has an intrinsic magnetic field3,4, which is aligned approximately antiparallel to Jupiter's magnetic field. Here we argue that these results imply that Ganymede has an outer silicate core surrounding a liquid (or partially liquid) inner core of iron or iron sulphide, and that the magnetic field is generated by dynamo action within this metallic core. lo also appears to have an intrinsic magnetic field5,6 (antiparallel to that of Jupiter), implying that it too has a metallic core7 in which the field is generated either by dynamo action or by magneto-convection.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on SpringerLink
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Additional access options:
Similar content being viewed by others
References
- Schubert, G., Spohn, T. & Reynolds, R. T. in Satellites (eds Burns, J. A. & Matthews, M. S.) 224–292 (University Arizona Press, Tucson, 1986).
Google Scholar - Anderson, J. D., Lau, E. L., Sjogren, W. L., Schubert, G. & Moore, W. B. Nature 384, 541–543 (1996).
Article ADS CAS Google Scholar - Kivelson, M. G. et al. Nature 384, 537–541 (1996).
Article ADS CAS Google Scholar - Gurnett, D. A., Kurth, W. S., Roux, A., Bolton, S. J. & Kennel, C. F. Nature 384, 535–537 (1996).
Article ADS CAS Google Scholar - Kivelson, M. G. et al. Science 273, 337–340 (1996).
Article ADS CAS Google Scholar - Kivelson, M. G. et al. Science 274, 396–398 (1996).
Article ADS CAS Google Scholar - Anderson, J. D., Sjogren, W. L. & Schubert, G. Science 272, 709–712 (1996).
Article ADS CAS Google Scholar - Turcotte, D. L. & Schubert, G. Geodynamics (Wiley & Sons, New York, 1982).
Google Scholar - Crary, F. J. & Bagenal, F. (abstr.) Bull. Am. Astron. Soc. 28, 1075 (1996).
ADS Google Scholar - Peale, S. J., Cassen, P. & Reynolds, R. T. Science 203, 892–894 (1979).
Article ADS CAS Google Scholar - Segatz, M., Spohn, T., Ross, M. N. & Schubert, G. Icarus 75, 187–206 (1988).
Article ADS Google Scholar - Veeder, G. J., Matson, D. L., Johnson, T. V., Blaney, D. L. & Gougen, J. D. J. Geophys. Res. 99, 17095–17162 (1994).
Article ADS Google Scholar - Cheng, A. F. & Paranicus, C. Geophys. Res. Lett. 23, 2879–2882 (1996).
Article ADS Google Scholar - Ross, M. N., Schubert, G., Spohn, T. & Gaskell, R. W. Icarus 85, 309–325 (1990).
Article ADS Google Scholar - Levy, E. H. Proc. Lunar Planet Sci. Conf. 10, 2335–2342 (1979).
ADS Google Scholar - Stevenson, D. J. Rep. Prog. Phys. 46, 555–620 (1983).
Article ADS CAS Google Scholar - Moore, W. B. & Schubert, G. (abstr.) Bull. Am. Astron. Soc. 28, 1139 (1996).
ADS Google Scholar - Bloxham, J. & Jackson, A. Rev. Geophys. 29, 97–120 (1991).
Article ADS Google Scholar - Khurana, K. K. J. Geophys. Res. (in the press).
- Frank, L. A. et al. Science 274, 394–395 (1996).
Article ADS CAS Google Scholar - Wienbruch, V. & Spohn, T. Planet. Space Sci. 43, 1045–1057 (1995).
Article ADS Google Scholar - Sterrett, K. F., Klement, W. Jr & Kennedy, G. C. J. Geophys. Res. 70, 1979–1984 (1965).
Article ADS CAS Google Scholar - Usselman, T. M. Am. J. Sci. 275, 278–290 (1975).
Article ADS CAS Google Scholar - McKinnon, W. B. (abstr.) Bull. Am. Astron. Soc. 28, 1076 (1996).
ADS Google Scholar - Malhotra, R. Icarus 94, 399–412 (1991).
Article ADS Google Scholar
Author information
Authors and Affiliations
- Department of Earth and Space Sciences, University of California, Los Angeles, California, 90095, USA
Gerald Schubert & Margaret G. Kivelson - Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California, 90095, USA
Gerald Schubert & Margaret G. Kivelson - Department of Mathematics, University of Exeter, Exeter, EX4 4QJ, UK
Keke Zhang - et Propulsion Laboratory, California Institute of Technology, Pasadena, California, 91109, USA
John D. Anderson
Authors
- Gerald Schubert
You can also search for this author inPubMed Google Scholar - Keke Zhang
You can also search for this author inPubMed Google Scholar - Margaret G. Kivelson
You can also search for this author inPubMed Google Scholar - John D. Anderson
You can also search for this author inPubMed Google Scholar
Rights and permissions
About this article
Cite this article
Schubert, G., Zhang, K., Kivelson, M. et al. The magnetic field and internal structure of Ganymede.Nature 384, 544–545 (1996). https://doi.org/10.1038/384544a0
- Received: 07 October 1996
- Accepted: 08 November 1996
- Issue Date: 12 December 1996
- DOI: https://doi.org/10.1038/384544a0
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.